Process for fixing nitrogen



UNITED STATES PATENT OFFICE.

CARL THEODOR THORS'SELL AND .HARALD LUDVIG REINHOYLD LUNDEN, or GOTTEN- BORG, SWEDEN, nssrenoas TO AKTIEBOLAGET KVAFVEINDUSTRI, or GOTTEN- BORG, SWEDEN.

No Drawing.

. zen of Sweden, residing at Kopmansgatan 20, Gottenborg, Sweden, have invented a certain new and useful Process for Fixing Nitrogen, of which the following is a specification.

This invention relates to a process for carrying out chemical reactions in the presence of metals in a finely divided form especially in the production of nitrogen compounds, when this is done by letting the nitrogen react upon a mixture ofcoal and alkali metals or alkaline-earth metals or their combinations at a high temperature for the forming of cyanid. In such reactions it was long ago known that the reaction is accelerated by adding some metals, for instance iron, manganese, etc. Such an addition of iron has been proposed inter (Ll 11a for instance in the German Patents Nos. 8238, 12350, 18945.

It has, however, become evident that the favorable result of this addition of metals will be still more and essentially increased,

iron compound, which does not contain other ingredients besides the iron than 7 hydrogen, oxygen, carbon and nitrogen.

Vhen heating the mass in the presence of coal these compounds will be reduced to iron in an extremely finely divided state. This iron is so finely divided that it is often pyrophorous. The mass is heated slowly in such a way that it is kept at a temperatureof 500-(300 I C. during a time not too Specification of Letters Patent.

Patented June 8, 1920.

Application filed July 9, 1919. Serial No. 309,739.

short, when the reduction to metallic iror takes place. In a continuous process thi' reduction takes place at the preheating or the mass. I

As the iron is used repeatedly in the process, 1t is only needed to add the same once at the start. Thus also iron salts that are somewhat more expensive, such as oxalate, may be used. The solution of oxalate penetrates into the coal and impregnates the same. In this way the iron will be finally dlvided and at the same time well intermingled.

Hydroxid of iron may also be used to advantage and then it may be produced cheaply in the following manner. A solution of ferrous sulfate is precipitated with ammonia and the ammonium sulfate obtained is recovered. The hydroxid of iron Many other metals, such as manganese,

. nickel, copper, etc., may be introduced in the mixture of reaction in exactly the same way andlead to the same result.

"Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

In a process for fixing nitrogen and forming cyanids, in which nitrogen is caused to react upon a heated mixture of carbonaceous material and alkali forming metal compounds, in the presence of finely divided metal, preparing said metal by reducing compounds containing no other elements than the metal, hydrogen, oxygen, carbon, and nitrogen, the reduction being carried on at a temperature lower than 550 C. and the metal then being introduced immediately into the zone of reaction.

In testimony whereof, we have signed our names to this specification in the presence of two subscribing witnesses.

\Vitnesses JOHN TOROLF CLARr'iUs, Aaron M. ANDERSON. 

